Objectives: Dysfunctions in stress biology are hypothesized to contribute to anxiety disorders, and to be ameliorated
during successful treatment, but limited clinical data exist to support this hypothesis. We evaluated
whether increases in morning cortisol and the diurnal cortisol slope, markers of stress biology, are associated
with clinical response to chamomile therapy among subjects with generalized anxiety disorder (GAD).

Methods: Among 45 subjects with DSM-IV diagnosed GAD in an open-label clinical trial of chamomile, salivary
cortisol was assessed for three days each pre- and post-treatment, at 8am, 12pm, 4pm, and 8pm. Mixed model
analyses assessed whether GAD symptom change predicted the degree to which cortisol levels changed during
treatment.

Conclusion: Increases in morning salivary cortisol and the diurnal cortisol slope are associated with symptom
improvement in chamomile treatment of GAD. Response to treatment for GAD could partially stem from normalization
of stress biology dysfunction, but further work involving establishing abnormalities within-sample,
ruling out of confounds (e.g., sleep), and a placebo control is necessary to conclude an amelioration effect.